---
title: "Global Infrastructure Modernisation"
outcome: "Modernised a global, multi-region estate at scale — ~1,000 VMs, flat-to-segmented networks, and a migration to Azure and Microsoft 365 — on a live 24/7 business."
summary: "Across global IT roles at Virtus Health and Linde Asia Pacific: a ~1,000-VM VMware estate managed centrally, a flat-to-segmented network redesign with SD-WAN and Aruba ClearPass, Palo Alto / FortiGate firewall redesigns, and migration to Azure (Blob, AVS) and Microsoft 365."
role: "Infrastructure Engineer · Virtus Health & Linde Asia Pacific"
period: "2019 – 2025"
stack: ["VMware / vSphere", "Azure (Blob, AVS)", "Microsoft 365", "SD-WAN", "Aruba ClearPass", "Palo Alto / FortiGate", "Veeam"]
featured: false
order: 40
cover: "global-infra-modernisation"
---

## Problem

Enterprise estates accrete. Flat networks, sprawling VM counts, aging firewalls, and
on-prem-only services become a security and operations drag. The work: modernise a global,
multi-region business that runs 24/7 — without breaking it.

## Constraints

- **Keep the lights on** — change a live, multi-region estate without downtime.
- **Security and compliance** — segmentation, patching, and auditability throughout.
- **Cost-aware** — modernise to cloud where it pays, justified through CapEx/OpEx cases.

## Design

Across global roles I ran and improved a **~1,000-VM VMware estate**, managed centrally for
the IT team and operated across regions including the UK. I re-segmented **flat sites into
isolated VLAN ranges** with ACLs, layering in **SD-WAN** and **Aruba ClearPass** with 802.1x
onboarding for a tiered, authenticated network. **Palo Alto / FortiGate** firewalls were
upgraded and redesigned around the new segmentation — RCA, staging through FortiManager, and
a flat-to-segmented redesign.

On the platform side: workloads and identity moved to **Azure** (Blob storage, AVS — lifting
existing vSphere environments) and **Microsoft 365**, with a **hybrid AD sync** I architected
to bridge on-prem and cloud identity. The estate work also covered an **ERP hardware refresh
with a new DR / mainframe solution**, file shares to Azure Blob over Kerberos auth, **Veeam**
backups, and a region-wide **PBX-to-VoIP** migration (RingCentral).

## Security & reliability decisions

- **Flat → segmented** — isolation by design, not by exception.
- **Authenticated access** (ClearPass, 802.1x) — the network knows who's on it.
- **Patched, current firewalls** — closing the easy doors first.
- **DR built in** — recovery designed, not assumed.

## Outcome

A more secure, segmented, cloud-leaning estate that's cheaper to run and easier to operate —
delivered against live-business constraints across multiple regions.

## Future improvements

The throughline from this work to the edge platforms: take the same segmentation and
identity rigour and express it as code, so a thousand-VM estate and a single edge node are
governed the same way.
